Many operating elements, particularly those used in motor vehicles, are provided with multiple functions. An example is a steering wheel control element having a rotating knurled handle that can be rotated endlessly and having pressure actuated switching functions. In order to prevent accidental operation, it is desired that various types of operations not be able to be executed concurrently.
An operating element that can be actuated by pressure and rotation as set forth in the above Technical Field is known from German patent application DE 10 2011 103 670 A1 (corresponds to U.S. Publication No. 2014/0034461). The operating element includes a cylindrically shaped input member (i.e., an actuator). The input member is connected to a rotatable shaft mounted on a carrier. The carrier is displaceable in a direction normal to the rotation axis of the shaft. A rotational sensor for detecting rotational movement of the input member is connected to the shaft. For example, the rotational sensor detects rotational movement of the input member through a code disk and a forked photoelectric sensor. The carrier is mounted on switching elements. The carrier displaces in the direction normal to the rotation axis when pressure is exerted on the input member. The displacement of the carrier causes the switching elements to activate. The switching elements produce electrical signals in response to being activated. The switching elements can be designed as micro-switches or as switch domes of a dome pressure sensitive mat.
The operating element further includes a detent wheel and a rotational spring-loaded lever. The detent wheel is next to the input member and is connected to the shaft. The detent wheel has along its perimeter an integrally molded detent curve. The lever includes a detent pin. The detent pin engages the detent curve of the detent wheel.
A rotational actuation of the input member follows in multiple sequential detent steps against the force exerted by the spring which acts on the lever. In a pressure actuation of the input member, the lever moves against a stop and prevents concurrent execution of a rotational actuation of the input member by blocking the detent wheel. For a rotational actuation of the input member, the bumps of the detent curve on the detent wheel deflect the lever, through which concurrent rotational motion is suppressed.
The detent wheel and the associated rotational spring-loaded lever require a relatively large amount of space.